The present invention relates to a seat for a vehicle provided with a lift mechanism and a designing method of the same.
In general, there are provided a reclining mechanism to adjust inclination of a seat back of a seat body, a slide mechanism to adjust a position, in a longitudinal direction, of the seat body, and a lift mechanism to adjust a position, in a vertical direction, of the seat body at a driver's seat of an automotive vehicle. A driver can drive the vehicle in an appropriate driving position by adjusting the position of the seat body by means of the above-described mechanisms according to a driver's physique (body size).
As disclosed in Japanese Patent Laid-Open Publication No. 2008-24014, the lift mechanism of the seat for the vehicle generally comprises a link mechanism which interconnects the slide mechanism placed on a vehicle floor and the seat cushion of the seat body. A link member which constitutes the link mechanism is driven so as to rotate around an axis extending in a vehicle width direction according to operation by an occupant, whereby the seat body can be elevated or lowered.
Since elevating/lowering of the seat body by means of the lift mechanism is achieved by a rotational move of the link member as described above, the seat body is moved not only in the vertical direction but in the longitudinal direction during its elevating/lowering. In general, the seat body is moved obliquely forward and upward when being elevated by the lift mechanism. In this case, a hip point of the driver is suppressed from moving away from a pedal, such as an accelerator pedal or a brake pedal, more properly compared with a case where the seat body is moved straight up.
Herein, the applicant of the present patent application has been researched an ideal driving position from various perspectives in order to develop the automotive vehicle which enables the driver to drive the vehicle at will.
For example, it is desired for the driver to drive the vehicle in a relaxed position from perspectives of securing the operability of the pedal operated by the driver and reducing fatigue of driver's legs. In order to attain the relaxed driving position, it is requested that angles of respective joints of a lower half body of the driver shown in FIG. 8 (an ankle's angle A, a knee's angle B, and hip's angle C) fall in respective appropriate ranges. Further, it is preferable that the position of driver's eyes be set in an appropriate eye-line zone Z1 (see FIG. 1) from perspectives of obtaining proper senses of speed and distance, a sense of safety during high-speed driving, or the like.
In general, the ankle's angle A, the knee's angle B, and the hip's angle C (see FIG. 3) are adjusted by the reclining mechanism and the slide mechanism, and the eye's position (height) of the driver is adjusted by the lift mechanism.
However, if the height adjustment by the lift mechanism is conducted after the above-described joint angles A, B, C have been adjusted by the slide mechanism and the like, there is a case where the ankle's angle A and the knee's angle B so change according to moving of a hip point HI that these angles A, B deviate from the respective appropriate ranges. In this case, readjustment by the slide mechanism and the like may be required for securing the appropriate driving position.